1. Field of the Invention
The present invention relates to a hybrid core rope used for a cableway of an elevator, a crane, a ropeway, a lift, or the like, facilities for fisheries such as trawling, and other purposes.
2. Description of the Related Art
There is a known fiber core rope in which a plurality of steel strands is twisted around a fiber core. By containing oil in the fiber core, the oil is supplied between the strands and between steel wires forming the strands during use. Thus, the fiber core rope has a favorable lubricating property between the fiber core rope and a sheave and the like. However, upon continuous use, the oil is gradually withdrawn, so that a diameter decrease rate of a rope diameter (a rate of reduction in rope diameter) is high. When the rope diameter is decreased, structural extension generated in the rope is also increased. Maintenance such as a task of shortening an extended part is unavoidably required.
There is also a known solid core rope in which a resin solid core (resin core) is used in place of the fiber core and a plurality of steel strands is twisted around this solid core. Since the steel strands are supported by the solid core, a diameter decrease rate of a rope diameter of the solid core rope is low, and extension is also small. However, since the solid core cannot contain oil, maintenance of regularly applying a lubricant from the outside is unavoidably required.
Japanese Patent No. 2892842 discloses a wire rope in which eight steel strands 12 are twisted around a core 11 provided with a core portion 14 made of plastic, rubber, or the like, and a natural fiber oil-containing portion 15 spirally wound around an outer periphery of the core portion 14. Although the core portion 14 provides suppression to some extent, due to the natural fiber (the oil-containing portion 15) wound around the entire outer periphery of the core portion 14, the fact remains that a diameter of the wire rope is decreased upon continuous use. It is thought that maintenance such as a task of shortening an extended part is required.